Fastener installation

ABSTRACT

A manually operated installation tool for fasteners such as expansion rivets of the type provided with an expander pin normally projecting from the rivet head and adapted to be forcibly driven into the rivet shank for expanding the shank. The installation tool comprises a hollow housing in which is disposed a reciprocable plunger. One end of the housing has a bore resiliently or frictionally accepting the expander pin projecting from the rivet head, with one end of the plunger proximate the end of the rivet pin, such that the tool is used for inserting the rivet into the rivet accepting apertures of a mechanical assembly, and the expander pin is subsequently forcibly driven into the rivet shank for expanding the shank as a result of manually displacing the plunger by manually applying pressure on the other end of the plunger provided with an appropriate knob.

United States Patent Taylor [54] F ASTENER INSTALLATION [72] Inventor:Philip W. Taylor, Howell, Mich.

[58] Field of Search ..227/51, 52, 53, 55, 60, 147, 227/149; 29/275,278, 280, 282

[56] References Cited UNITED STATES PATENTS 2,430,532 11/1947 Rayburn..227/147 x 3,030,849 4/1962 Bisbing et al. ..227/52 x PrimaryExaminer-Granville Y. Custer, Jr. Att0rney-Hauke, Gifford and Patalidis1 51 Oct. 3, 1972 [57] ABSTRACT A manually operated installation toolfor fasteners such as expansion rivets of the type provided with anexpander pin normally projecting from the rivet head and adapted to beforcibly driven into the rivet shank for expanding the shank. Theinstallation tool comprises a hollow housing in which is disposed areciprocable plunger. One end of the housing has a bore resiliently orfrictionally accepting the expander pin projecting from the rivet head,with one end of the plunger proximate the end of the rivet pin, suchthat the tool is used for inserting the rivet into the rivet acceptingapertures of a mechanical assembly, and the expander pin is subsequentlyforcibly driven into the rivet shank for expanding the shank as a resultof manually displacing the plunger by manually applying pressure on theother end of the plunger provided with an appropriate knob.

8 Claims, 4 Drawing Figures BACKGROUND OF THE INVENTION It is commonpractice to utilize fasteners such as expansion rivets to assemblediverse thin metal or thin plastic parts together, or for mounting, forexample, parts made of sheet metal or sheet plastic on a sheet metal orsheet plastic mounting panel. Expansion rivets are commonly made of asubstantially soft metal or they are made of plastic, and they areprovided with an expander pin disposed in a longitudinal bore throughthe rivet head and body or shank. The expander pin normally projectsfrom the rivet head and upon being forcibly driven, as a result ofimpact by a hammer or a like tool, into the rivet shank which preferablyis crossslotted so as to facilitate its expansion causes the shank toexpand and spread in such manner as to maintain in assembly mechanicalparts provided with aligned rivet accepting apertures. Expansion rivetsare used extensively at the present for attaching to a mounting paneldiverse electrical components, wire harness straps, wiring guideways orducts, and like elements. One advantage of using the expansion rivetsfor installing components on a panel provided with appropriate mountingapertures is that it is only necessary to have access to the rivet headon one side of the panel in order to secure the component to the panelby driving into the rivet the projecting expander pin. It is commonpractice to manually insert the rivet shank into the rivet acceptingapertures in the component and in the panel, and to subsequently strikeor hit the end of the expander pin projecting from the rivet head with ahammer, a screwdriver handle, or a like convenient tool. In narrow orcramped places it is obviously difficult to manually insert the rivet inposition, and when elements are mounted on a vertical panel or on thetop panel of an electrical cabinet, considerable difficulties are met inattempting to obtain correct placement of the rivets and holding of therivets in position prior to impacting the expander pin.

The installation tool of the present invention provides a convenientmeans for grasping and holding an expansion rivet on the end of the toolfor insertion of the rivet shank into the aligned rivet acceptingapertures of an assembly and for holding the rivet securely in positionduring impacting of the expander pin by means of a plunger disposed inthe tool housing and actuated by a convenient knob disposed on the otherend of the tool so as tobe accessible to the user of the tool.

The many objects and advantages of the present invention will becomeapparent to those skilled in the art when the following description ofan example of the best mode contemplated for practicing the invention isread in conjunction with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective viewof the fastener installation tool of the invention in use for installingan expansion rivet to assemble an electrical wiring duct on a panel;

FIG. 2 is an exploded perspective view of the tool shown at FIG. 1;

FIG. 3 is a longitudinal sectional view of the installation tool of theinvention shown in the course of inserting an expansion rivet into therivet accepting apertures of an assembly; and

FIG. 4 is a view substantially similar to FIG. 3 but showing theinstallation tool of the invention while being used for driving therivet expander pin for ex'- panding the rivet shank.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in thedrawings, an example of a fastener installation tool according to thepresent invention takes the form of a hollow elongated housing 10 madeof any convenient material such as a metallic material but preferablymade of plastic for the sake of low manufacturing costs and ease ofassembly. A portion of the periphery of the hosing 10 is provided with aroughened surface, as shown at 12, for the purpose of affording a bettergrip to the hand of the tool user. One end of the housing 10 ispreferably tapered as shown at 14, so as to provide a substantiallyslender end permitting introducing the tool end and an expansion rivet16 carried onthe end thereof into a narrow or cramped space forinserting the rivet shank into the aligned rivet accepting apertures ofan assembly. Suchassembly, as illustrated at FIG. 1, may consist of asupport panel schematically shown at 18 on which it is desired to mountor fasten a mechanical component which, as illustrated, consists, of aU-shaped electrical wiring channelway, duct or guideway as shown at 20.The illustrated guideway is provided with a substantially flat mountingbase 22 having longitudinal extending apertures or slots 24 which arealigned with pre-drilled mounting holes 26 in the panel 18 or,alternately, the locations of the mounting apertures 24 of the guidewayare marked on the panel and appropriate mounting holes 26 are drilledfor mounting of the guideway thereon. The mounting of the guideway onthe panel 18 is conveniently effected by means of the expansion rivets16, made of soft metal or preferably made of a plastic which, is bestseen in FIGS. 3 and 4, comprises an enlarged head 28 and an integralshank 30 provided with cross-slots as shown at 32 for the purpose offacilitating expansion of the shank after insertion thereof in themounting aperturs 24 and 26. An expander pin 34, which normally projectsfrom the rivet head 28, is adapted to be driven forcibly into asubstantially narrow bore 36 axially disposed within the rivet shank 30.After the rivet shank 30 is inserted in the aligned mounting apertures24 and 26, the expander pin 34 is driven flush with the surface of therivet head 28 so as to cause expansion of the shank 30, such expansionbeing facilitated by the presence of the crossslots 32 permitting therivet shank segments between successive cross-slots to be effortlesslyexpanded by the expander pin 34. Such expansion rivet structure isconventional and well known in the fastener art.

The housing 10 of the installation tool has an internal bore 38, which,in the example illustrated, is separated from a reduced diameter boreportion 40 by a wall 42 through which is slidably disposed a plunger 44in the form of a steel rod, or the like, having an outer diametersubstantially equal to the outer diameter of the rivet pin 34. A handlein the form of a substantially large diameter disc or knob 46 is rigidlyfastened to one end of a cylindrical member 48, the other end of whichis adapted to be mounted on the end of the plunger rod 44 for example byway of the plunger rod 44 being press-fitted into an axial bore 50formed in the cylindrical member 48 as more clearly shown at FIG. 3. Thecylindrical member 48 has a reduced diameter portion 52 provided at bothends thereof with an annular abutment as shown at 54 and 56. A sleeve 58having a bore 60 slidably accepting the reduced diameter portion 52 ofthe cylindrical member 48 is fastened, such as by gluing, cementing orany other convenient way, to the counterbored end 62 of the housing 10.Preferably, a coil spring 64 is mounted between the separation wall 42and the end of the cylindrical member 48 so as to normally urge thecylindrical member 48 in a leftward direction, as shown in FIG. 3, withthe annular abutment 56 thereof engaged with the right end of the sleevemember 58, thus retracting the end 66 of the plunger 44 a predetermineddistance within the reduced diameter portion 40 of the housing internalbore. The length of the plunger 44 and the dimensions of the diverseelements are such that with the spring 64 retracting the plunger 44 inthe position shown at FIG. 3, the end 66 of the plunger is clear of theend ofa rivet expander pin 34 inserted in the end of the reduceddiameter portion 40 of the tool housing bore which is provided with aholding sleeve 68 disposed therein proximate the end of the housing. Thesleeve 68 is made of a resilient material such as vinyl plastic or thelike and has an internal diameter slightly less than the outer diameterof the expander pin 34 such as to provide a frictional resilientengagement between the inner wall surface of the sleeve and theperipheral surface of the expander pin. In this manner an expanion rivetl6 placed on the end of the housing 10 with its expander pin 34 normallyintroduced into the sleeve 68 is securedly held such that the tool ofthe invention can be used as a holding device, as shown at FIG. 1, forcarrying on its end an expansion rivet 16 for introducing the shank 32thereof into the aligned mounting apertures 24 and 26. Once the rivet isinserted in position, a moderate pressure manually applied on the discknob 46 causes displacement of the cylindrical member 48 to the positionshown at FIG. 4 wherein the annular shoulder 54 engages the right handend of the sleeve 58 affixed to the housing end, thus in turn displacingthe plunger 44 against the bias of the spring 64 to a position whereinthe end 66 of the plunger is substantially flush with the surface of therivethead 28, thus driving the rivet expander pin 34 into the rivetshank 30, for in turn expanding the shank 30 to securely hold the rivetin position in the rivet accepting apertures 24-26. The length of thereduced diameter portion 52 of the cylindrical member 48 is thepermissible reciprocation stroke of the plunger 44. Because the discknob 46 has a substantially area as compared to the area of the plungerend 66, only a small amount of pressure on the knob is required tofaultlessly drive the expander pin 34 into the rivet shank 30.

It is obvious that the diverse elements forming the installation tool ofthe invention are designed for easy assembly and that, for example, thecylindrical member 48 is made in two parts so at to permit insertion ofthe sleeve or collar 58 over the reduced diameter portion 52 of thecylindrical member 48. The rivet holding sleeve 68 may be made removableand replaceable by sleeves having bores of different diameters so as toaccept rivets of different sizes within a predetermined ran e, or thetool may be made with a demountable tip an provided with a plurality oftips each having a sleeve of a different size for accepting rivets ofdiverse dimensions within a predetermined range.

Having thus described the invention by way of an example of practicalembodiments thereof, given for illustrative purpose only,

What is claimed as new is as follows:

1. An installation tool for installing in a rivet accepting aperture anexpansion rivet of the type having a head, a shank and an expander pinnormally projecting from said head and adapted to be forcibly driven inan axially aligned bore in said rivet shank for expanding said shank,said installation tool comprising an elongated housing having a boreextending axially therein, a plunger slidably disposed in said bore, aportion of said bore proximate an end of said housing having apredetermined diameter for frictional engagement of said rivet expanderpin therein for holding said rivet in the end of said housing forinsertion of said rivet shank in said rivet accepting aperture, andmeans on one end of said plunger projecting from the other end of saidhousing for manually reciprocating said plunger relative to said housingfor causing the other end of said plunger to forcibly drive saidexpander pin into said rivet shank for expanding said shank to installsaid rivet in said rivet accepting aperture.

2. The installation tool of claim I further comprising spring bias meansnormally maintaining said plunger with the other end thereof retractedfrom the portion of the bore at the end of said housing adapted toaccept said expander pin projecting from said rivet head.

3. The installation tool of claim 1 wherein said end bore portion ofsaid housing adapted to accept said expander pin projecting from saidrivet head is defined by a resilient material tubular insert mounted insaid housing and having an inner diameter slightly smaller than theouter diameter of said expander pin.

4. The installation tool of claim 1 wherein said means on the end ofsaid plunger projecting from said housing is a relatively large diameterknob.

5. The installation tool of claim 1 further comprising abutment meansdependent from said plunger and said housing for limiting thedisplacement of said plunger to an amount sufficient for causing saidexpander-pin to be driven in said rivet shank with the end of said pinnormally projecting from said rivet head substantially flush with saidrivet head.

6. The installation tool of claim 5 wherein said abutment meanscomprises a stationary sleeve mounted on the other end of said housing,a cylindrical member mounted on said first mentioned end of the plungerslidably disposed coaxially within said sleeve member and an annularshoulder proximate each end of said cylindrical member and each adaptedfor engagement with one of the ends of said sleeve member for limitingthe reciprocation of said plunger.

7. The installation tool of claim 1 wherein a portion of said housing isperipherally provided with a roughened surface.

8. The installation tool of claim 1 wherein said housing has an endportion gradually tapering to a diameter

1. An installation tool for installing in a rivet accepting aperture an expansion rivet of the type having a head, a shank and an expander pin normally projecting from said head and adapted to be forcibly driven In an axially aligned bore in said rivet shank for expanding said shank, said installation tool comprising an elongated housing having a bore extending axially therein, a plunger slidably disposed in said bore, a portion of said bore proximate an end of said housing having a predetermined diameter for frictional engagement of said rivet expander pin therein for holding said rivet in the end of said housing for insertion of said rivet shank in said rivet accepting aperture, and means on one end of said plunger projecting from the other end of said housing for manually reciprocating said plunger relative to said housing for causing the other end of said plunger to forcibly drive said expander pin into said rivet shank for expanding said shank to install said rivet in said rivet accepting aperture.
 2. The installation tool of claim 1 further comprising spring bias means normally maintaining said plunger with the other end thereof retracted from the portion of the bore at the end of said housing adapted to accept said expander pin projecting from said rivet head.
 3. The installation tool of claim 1 wherein said end bore portion of said housing adapted to accept said expander pin projecting from said rivet head is defined by a resilient material tubular insert mounted in said housing and having an inner diameter slightly smaller than the outer diameter of said expander pin.
 4. The installation tool of claim 1 wherein said means on the end of said plunger projecting from said housing is a relatively large diameter knob.
 5. The installation tool of claim 1 further comprising abutment means dependent from said plunger and said housing for limiting the displacement of said plunger to an amount sufficient for causing said expander pin to be driven in said rivet shank with the end of said pin normally projecting from said rivet head substantially flush with said rivet head.
 6. The installation tool of claim 5 wherein said abutment means comprises a stationary sleeve mounted on the other end of said housing, a cylindrical member mounted on said first mentioned end of the plunger slidably disposed coaxially within said sleeve member and an annular shoulder proximate each end of said cylindrical member and each adapted for engagement with one of the ends of said sleeve member for limiting the reciprocation of said plunger.
 7. The installation tool of claim 1 wherein a portion of said housing is peripherally provided with a roughened surface.
 8. The installation tool of claim 1 wherein said housing has an end portion gradually tapering to a diameter at most equal to the diameter of said rivet head. 